The altering of hair color is an important area of modern cosmetics. Various bleaching agents with varying bleaching capacity are available on the market for the purpose of lightening the natural hair color or for bleaching. The basic principles of bleaching methods are known to the person skilled in the art and can be researched in relevant monographs by, for example, Kh. Schrader, Grundlagen and Rezepturen der Kosmetika, 2nd edition, 1989, Dr. Alfred Hüthig Verlag, Heidelberg, or W. Umbach (Ed.), Kosmetik, 2nd edition, 1995, Georg Thieme Verlag, Stuttgart, New York.
The oxidizing agents contained in bleaching agents have the ability to lighten the hair fiber by means of the oxidative breakdown of the hair's natural pigment, melanin. For a moderate bleaching effect, the use of hydrogen peroxide—optionally with the use of ammonia or other alkalizing agents—is sufficient as an oxidizing agent on its own; for a stronger bleaching effect, a mixture of hydrogen peroxide and peroxodisulfate salts and/or peroxomonosulfate salts is conventionally used. Lightening is, however, also associated with damage to the hair, as not only the natural coloring components of the hair but also the other structural constituents of the hair are damaged by oxidation. Depending on the extent of the damage, it can range from coarse, brittle and tangled hair, through reduced resistance and breaking strength of the hair, to breakage of the hair. Larger amounts of hydrogen peroxide and optionally peroxodisulfates tend to be associated with greater damage to the keratin fiber. Although the bleaching agents hitherto available on the market generally have good lightening capacity, they cannot be regarded as ideal because of the hair damage, long application times and possible skin irritation caused by the high concentrations of oxidizing and alkalizing agents. There is therefore still a need for lightening agents that have a good lightening capacity without at the same time damaging the hair fiber.
Especially in cases where bleaching is performed repeatedly, different sections of the hair can be damaged to varying degrees. Lengths of hair that have already been bleached several times or have also previously been subjected to other hair treatments often show greater signs of damage than the comparatively untreated sections close to the hairline. The obvious appearance of damaged hair, in particular split ends and dull tips, is a problem and is undesirable for consumers.
The bleaching of hair using a combination of cationic acyl pyridinium derivatives and hydrogen peroxide combined with certain coactivators is known from WO2009/135700 A1. This is intended to achieve a strengthening of the lightening effect.
It could not be inferred from the prior art to date that a combination of certain acyl pyridinium derivatives, hydrogen peroxide and special polysaccharides not only improves the lightening capacity in comparison to a standard bleach containing hydrogen peroxide, as is already known, but also leads to a more uniform, glossier appearance, especially at the tips of the bleached hair.
The object of the present invention is therefore to provide an agent that not only lightens the hair but also brings about a more uniform color result from the hairline to the tip after lightening and leads to an appearance with glossier hair.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with this background of the invention.